This invention relates to vibrating tampers or tamping machines that include an engine section and a tamper section. More particularly the invention relates to a tamper with side-by-side engine and tamper sections reducing structural height, but with a minimum of joints and frictional sliding guides in the structural interconnection and power transmission connections between the engine and tamper sections.
An appreciable problem in connection with tamping machines of the type in question has been the difficulty of achieving low structural height, which is important for achieving the greatest possible stability. By locating the engine level with and beside the tamper section, instead of immediately above it, the structural height of the tamping machine can be substantially reduced. However, this arrangement gives rise to the problem of reducing the number of joints and frictional sliding guides in the mounting and power transmission systems which make possible relative movement between engine and tamper sections.
In known constructions of this kind link arms have connected the engine and tamper sections. These have been arranged horizontally in the direction of forward movement of the tamper. The link arms have had hinged connections at both the engine and tamper sections. Also in known constructions, a lever pivoted on the motor section, and driven from a connecting rod journalled eccentrically on the engine drive shaft, has been employed to transmit power to the tamper section from the engine. In this way, the rotational motion of the drive shaft has been converted to chiefly vertical reciprocating motion applied to the tamper. Although this construction has achieved the desired reduction in structural height, the power and structural interconnections have not been satisfactorily strong, and too many joints in the interconnecting parts have complicated the structure more than desired. The requirements of the members interconnecting the tamper and engine sections are made more troublesome by the need to withstand severe oblique loads which the tamper encounters in operation. Moreover, the link arm type of interconnection or suspension system also imparts a fairly substantially horizontal component in the relative motion between the engine and tamper section. This horizontal component must be compensated, for example by specially arranged cushioning.